Integrated microwave-to-optical single-photon transducer with strain-induced electro-optic material

Patent metadata

Field	Value
Publication number	US-9857609-B2
Application number	US-201715609701-A
Country	US
Kind code	B2
Filing date	May 31, 2017
Priority date	Feb 8, 2016
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.

First claim

The invention claimed is:

1. A quantum computing device, comprising:
a qubit configured to provide a first signal at a first frequency;
a transducer coupled to the qubit, comprising:
a substrate having a cylindrical cavity with a diameter that supports whispering gallery modes at the first frequency;
a central pin in the cavity; and
a resonator directly under the central pin, having a crystalline structure that generates an electro-optic effect when exposed to electrical fields, wherein an electric field of the input signal modulates a second signal at a second frequency in the resonator via the electro-optic effect; and

a waveguide, optically coupled to the resonator, that is configured to convey the modulated second signal away from the resonator.

2. The quantum computing device of claim 1 , wherein the transducer further comprises a superconducting film that is formed directly on an inner surface of the cavity and on an outer surface of the central pin.

3. The quantum computing device of claim 1 , wherein the resonator is formed from a first material having grooves in a top surface with a second material formed in the grooves, wherein the second material creates a strain in a crystalline structure of the first material to generate the electro-optic effect in the resonator.

4. The quantum computing device of claim 3 , wherein the resonator comprises an optical disc structure.

5. The quantum computing device of claim 3 , wherein the resonator comprises an optical ring structure.

6. The quantum computing device of claim 3 , wherein the first material includes silicon and the second material includes silicon germanium.

7. The quantum computing device of claim 1 , wherein the central pin comprises a surface facing toward the resonator, the surface having a ridge along an outer circumference.

8. The quantum computing device of claim 7 , wherein the ridge on the central pin is positioned directly on the resonator.

9. The quantum computing device of claim 7 , wherein the ridge on the central pin is positioned above the resonator to provide a small gap between the ridge and the resonator.

10. The quantum computing device of claim 1 , wherein the first frequency is a microwave frequency and the second frequency is an optical frequency.

11. The quantum computing device of claim 1 , wherein the central pin is coaxial with the cavity.

12. The quantum computing device of claim 1 , wherein the transducer further comprises a second cavity underneath the resonator having a same diameter as the cavity in the substrate.

13. The quantum computing device of claim 1 , wherein the transducer is coupled to the qubit via a superconducting channel disposed within the substrate.

14. The quantum computing device of claim 1 , wherein the cavity includes a radius of about 2.5 millimeters and the central pin includes a radius of about 2 millimeters.

15. The quantum computing device of claim 1 , wherein the resonator includes a diameter that provides three modes at frequencies ω op −ω q for a red-sideband, ω op for a carrier, and ω op +ω q for a blue-side band, with ω q being a microwave frequency of a microwave resonator.

16. A quantum computing device, comprising:
a qubit configured to provide a first signal at a first frequency;
a transducer coupled to the qubit, comprising:
a substrate having a cylindrical cavity with a diameter that supports whispering gallery modes at the first frequency;
a central pin in the cavity, wherein an outer surface of the central pin and an inner surface of the cavity have a superconducting film formed directly thereon; and
a resonator directly under the central pin, having a crystalline structure that generates an electro-optic effect when exposed to electrical fields, wherein an electric field of the input signal modulates a second signal at a second frequency in the resonator via the electro-optic effect, the resonator being formed from a first material having grooves in a top surface with a second material formed in the grooves, wherein the second material creates a strain in a crystalline structure of the first material to generate the electro-optic effect in the resonator; and

a waveguide, optically coupled to the resonator, that is configured to convey the modulated second signal away from the resonator.

17. The quantum computing device of claim 16 , wherein the first material includes silicon and the second material includes silicon germanium.

18. The quantum computing device of claim 16 , wherein the central pin comprises a surface facing toward the resonator, the surface having a ridge along an outer circumference.

19. The quantum computing device of claim 16 , wherein the transducer further comprises a second cavity underneath the resonator having a same diameter as the cavity in the substrate.

20. The quantum computing device of claim 16 , wherein the transducer is coupled to the qubit via a superconducting channel disposed within the substrate.

Assignees

• IBM

Inventors

• Bishop Lev S
• FILIPP Stefan
• Gambetta Jay M
• Orcutt Jason S
• Paik Hanhee

Classifications

• G02F2201/17

  Multi-pass arrangements, i.e. arrangements to pass light a plurality of times through the same element, e.g. by using an enhancement cavity · CPC title

• G02B6/29341 Primary

  Loop resonators operating in a whispering gallery mode evanescently coupled to a light guide, e.g. sphere or disk or cylinder (evanescent coupling for sensing fluorescence G01N21/648) · CPC title

• B82Y20/00

  Nanooptics, e.g. quantum optics or photonic crystals · CPC title

• H01P7/086

  Coplanar waveguide resonators (H01P7/088 takes precedence) · CPC title

• G02F1/0102

  Constructional details, not otherwise provided for in this subclass · CPC title